Power slips with warning signal means



April 8, 1958 B. F. KELLEY POWER SLIPS WITH WARNING SIGNAL MEANS Filed Nov. 4; 1955 2 Sheets-Sheet 1 Ben/am? ff ffe/ley IN VEN TOR.

ATTO/FA/fy Apnl 8, 1958 B. F. KELLEY 2,829,617

POWER SLIPS WITH WARNING SIGNAL MEANS Filed Nov. 4, 1955 2 Sheets-Sheet 2 /l I K 1 l 50 /44/4/ 42 45% J4 J5 49 /0 4 fiefl om/n f /(//65/ A? l 37 INVENTOR.

T'W" I INIIHNN "MUN. BY I United States Patent POWER SLIPS WITH WARNING SIGNAL MEANS Benjamin F. Kelley, Tulsa, Okla.

Application November 4, 1955, Serial No. 545,016

Claims. (Cl. 116--65) This invention relates to power-operated pipe slips employed in rotary well drilling and more particularly to signal means employed in conjunction with such poweroperated slips to provide the operator with a warning against improper actuation of such slips.

In rotary drilling, toothed wedges, commonly termed slips are employed to support the drill pipe during the periods in running a pipe in and out of the well when the elevators or hoisting mechanism must be disconnected from the pipe string to permit removal from or addition to the string of pipe sections.

In recent years the operation of inserting and removing the slips has been performed in increasing measure by automatic power-operated devices, commonly referred to as power slips. One form of such power slips is disclosed in my U. S. Patent No. 2,340,597, issued February 1, 1944. In a power-operated slip of the character described, the slips are suspended from a yoke carried by an operating arm which, in one form of device, is secured to a vertically disposed sleeve slidable on a hollow supporting post and secured to a piston rod actuated by a piston slidably mounted in the bore of the post and operated by introduction of air or other pressure fiuid into the interior of the post on opposite sides of the piston, depending on whether the slips are to be raised or lowered.

In the operation of such power slips, it sometimes occurs that the operator, either through carelessness or oversight, will turn the pressure fluid into the operating cylinder so as to cause the slips to be raised at a time when the pipe string, being supported on the slips, is not secured to the drawworks or hoisting mechanism of the derrick. In such a case, unless remedial action is taken immediately, the slips may release the pipe and allow it to drop into the well with consequent serious damage to the well and to the dropped pipe.

The present invention, therefore, has for its principal object the provision of an improvement in automatic slips by which an audible signal will be generated whenever the power fluid is introduced into the power cylinder at an improper time.

A more specific object is to provide in an air-operated power slip an air actuated whistle which will provide an audible signal upon improper actuation of the Dower slips.

Other and more specific objects and advantages of this invention will become apparent from the following detailed description when read in conjunction with the accompanying drawing which illustrates a useful embodiment in accordance with. this invention.

In the drawing:

Fig. 1 is a side elevational view, partly in section, of a power slip, the actuating cylinder being shown in longitudinal quarter section and its relation to the signalling device when the slips are in the down position;

Fig. 2 is a view of the power cylinder similar to Fig. 1, showing. the position of the parts when the slips are in the raised position;

Fig. 3 is a longitudinal sectional view of a pneumatic till ice

whistle element of the device in accordance with this in vention;

Fig. 4 is an end elevational view of the whistle taken generally along line 4-4 of Fig. 3; and

Fig. 5 is a generally schematic view of a drilling derrick illustrating the position of the power slips in the structure.

Referring first to Fig. 5, there is shown the usual drilling derrick 6 equipped with the usual drawworks, including the winch 7, crown blockB, travelling block 9, cable 10, and elevators 11 which are employed to raise and lower the string of drill pipe in the usual and well-known manner. The rig is equipped wtih the usual rotary table 13 through which the pipe string 12 is raised. and lowered, the rotary table being provided with a conventional slip bowl 14 (Fig. 1) through which the pipe string extends and into which slips, indicated by the broken lines 15 in Fig. 1, are inserted to wedgingly support the pipe string and from which the slips may be removed by means of a power slip, designated generally by the numeral 16, of the general character described in my aforesaid U. S. Patent No. 2,340,597.

The power slips will ordinarily comprise a horizontally disposed yoke 17 to which the slips 15 are suitably hinged ly linked by means of the linkages 18, whereby raising and lowering of the yoke will correspondingly raise and lower the slips while, at the same time, producing related radial movement of the slips, by which the slips will be caused to release or grasp the pipe, as the case may be. Yoke 17 is carried by an arm member 19 which is securely clamped to avertically disposed sleeve 20 slidable over the exterior of a hollow post 21 which is firmly secured in upright position to a portion of the derrick structure, as by means of the beam 22 (Fig. l). Secured to the lower end of post 21 is a cylinder 23, the upper end of which is closed by an end plate 24, and the lower end by an end plate 25. A piston 26 is slidably mounted in cylinder 23 and is connected to a piston rod 27 which extends slidably through end plate 24 and thence through the bore of post 21 projecting through the upper end thereof. The upper end of piston rod 27 is rigidly secured to a cap 28 forming an upper end portion of sleeve 26. With this arrangement, it will be seen that as piston 26 is reciprocated in cylinder 23, sleeve 20 will be correspondingly raised and lowered and Will thereby raise and lower arm 19 and yoke 17 to operate the slips. End plate 24 is effectively clamped between annular flanges 29 and 32 carried by the adjacent ends, respectively, of post 21. and cylinder 23 to thereby form these elements into a unitary structure.

End plate 25, at the lower end of cylinder 23, has an opening 31 through which pressure fluid, such as air, may be introduced into, or removed from, the portion of cylinder 23 below piston 26. End plate 24- is provided with a pressure fluid passage 32 through which pressure fluid such as air may be introduced into or removed from the portion of cylinder 23 above piston 2a. Thus, introduction of pressure fluid through opening 31 below the piston will raise the slips, while introduction of pressure fluid through passage 32 will move piston 26 downwardly and lower the slips. It will be understood that when the piston is moving upwardly, pressure fluid above the piston will be discharged through passage 32 and when the piston is moving downwardly, pressure fluid below the piston will discharge through opening 31.

Pipe 33 is connected into opening 31 for placing the lower end of cylinder 23 into communication with a source (not shown) of pressure fluid, such as compressed air, which is connected to pipe 33. A pipe 34 is connected to passage 32 for placing this passage in communication with the source ofpressurefiuid.

A by-pass pipe 35 is connected into pipe 33, as by means of the T fitting 36 (Fig. l) and leads to an airoperated whistle device, designated generally by the numeral 37, which is suitably supported adjacent the lower end of sleeve 20, the whistle member being securely mounted on flange 29.

The construction of whistle 37 is best shown in Figs. 3 and 4 and comprises a horizontally disposed generally tubular body 40 having a transverse partition 41 therein intermediate the ends of body 40, the partition being provided with an axial passage 42 providing communication between a pressure cylinder 43 on one side of partition 41 and a plunger cylinder 44 on the opposite of partition 41. A valve 45 is reciprocably mounted in pressure cylinder 43 for movement into opening and closing position over passage 42, the valve being resiliently urged to the closed position by means of a spring 46 disposed in compression between valve 45 and a screw cap 47 which forms a closure for the outer end of cylinder 43 and is provided with a central opening 47a forming the inlet connection between cylinder 43 and pipe 35. Valve 45 is mounted on a stem 48 which has an extension 49 pro jecting axially through passage 42 into the interior of plunger cylinder 44. A plunger 50 is slidably mounted in the bore of plunger cylinder 44 and projects through the outer end thereof. The outer end of plunger 50 is bifurcated to provide a vertically disposed slot 51 in which is journalled a roller 52. The rim of roller 52 extends into a guide slot 53 formed in a base member 54 on which body 46 is mounted. The inner end of plunger Ell carries a sealing cup 55 secured about a pin 56 which projects inwardly of cylinder 44 from the inner end of plunger 5%) and is in registration with stem extension 49. An air whistle 57 of any well-known and generally conventional construction, adapted to emit an audible whistle when air is introduced into it, is mounted on body 40 and cornmunicates with the interior of plunger cylinder 44 at a point between partition 41 and the inner end of plunger 50.

The arrangement of the parts of the whistle device 37 is such that when valve 45 is in the closed position over passage 42, under the urging of spring 46, stem 49 will project into plunger cylinder 44 a distance suflicient to engage the end of pin 56 and push plunger 50 outwardly so as to bring the periphery of roller 52 closely adjacent to the outer surface of post 21, as best seen in Fig. 3. Inward movement of the plunger 50 will act through engagement of pin 56 with stem extension 4-9 to push valve 45 away from the end of passage 42 and thereby open communication between pressure cylinder 43 and plunger cylinder 44.

Operation of the device is as follows: When the slips are moved to the pipe-wedging position, illustrated in Pig. 1, at which they support pipe string 12, sleeve 20 will have moved down post 21 a suflicient distance so that its lower end 20a will be inserted between the periphery of roller 52 and the outer surface of post 21. This insertion of end 2011 will force plunger 50 inwardly of plunger cylinder 44 and, acting through the engagement of pin 56 with the end of stem extension 49, will move valve 45 away from passage 42 and place the power cylinder 43 and plunger cylinder 44 in communication with each other.

In this position of the parts of the device, piston 26 will be in the down position shown in Fig. 1. When it is desired to raise the slips, air will be turned into the lower end of cylinder 23 below piston 26 through pipe 33 and opening 31. At the same time, a portion of the air will be diverted through by-pass 35 into pressure cylinder 43 of the whistle device. Since valve 45 is in the open position, air will flow through passage 42 into plunger cylinder 44 and thence into and through whistle 57 causing the latter to start to blow and produce an audible signal. if the elevator or hoisting equipment has not previously been connected to pipe string 12 and has not taken the usual lifting strain on the pipe string, it will be seen that the whistle will continue to blow. This signal will continue because the weight of the pipe string will be on the slips and will continue to blow as long as the Weight of the pipe remains on the slips or until hoisting device lifts the pipe weight off the slips. During this interval, the whistle would continue to blow and would thereby advise the operator that the lifting pressure has been put on the power slips. The continuance of the signal would be a warning to the operator that the air has been improperly turned into the power slip cylinder.

When the elevators or other hoisting equipment are properly connected to the pipe string and the lifting strain taken thereon, then if air is turned into the lower end of cylinder 23, the weight of the pipe being off of the slips, the latter will be raised quickly. Raising of the slips will, of course, be accompanied by upward movement of sleeve 20 and will draw end 20:: from between roller 52 and post 21. Withdrawal of the sleeve in this manner will allow plunger 50 to move back to its initial position, shown in Fig. 3, in which position valve 45 will immediately move to the closed position shutting off air to the whistle. Thus, when the pipe is properly supported by the drawworks, introducing the air into the lifting cylinder will produce, at most, only a very short blast of whistle 57 during the very brief interval required to start the slips out of the slip bowl. This obviously can be readily contrasted with the previously described situation in which the slips remain in their down position for an appreciable length of time while the whistle continues to blow.

It will be understood that various changes and modifications may be made in the details of the illustrative embodiment within the scope of the appended claims but without departing'frorn the spirit of this invention.

What I claim and desire to secure by Letters Patent is:

1. In power slips, a cylinder, piston means reciprocable in said cylinder for moving pipe-gripping slips to and from pipe-releasing positions, conduit means for introducing pressure fluid into said cylinder for reciprocating said piston means therein, and fluid pressure actuated signal means connected to said conduit means, said signal means being actuatable by the introduction of pressure fluid from said conduit means into said cylinder for urging the piston means to the pipe-releasing position to produce a signal indicative thereof.

2. A power slip as defined by claim 1 wherein said pressure fluid is air and said signal means is an air-actuated whistle.

3. A power slip as defined by claim 1 wherein said signal means includes a hollow body, a partition in said body dividing the same into a valve chamber and a plunger chamber, the valve chamber being connected to said conduit means, a port in said partition providing communication between said chambers, a valve in said valve" chamber for opening and closing said port, means resiliently urging said valve to the port-closing position, a sealed plunger slidable in the plunger chamber and projecting through the outer end thereof, said plunger being engageable with said valve to move the latter to the portopening position when the plunger is moved inwardly of the plunger chamber, a fluid pressure actuated whistle communicating with the plunger chamber between the inner end of the plunger and said partition, the outer end of said plunger being engageable by an actuating member carried by said piston means when the latter is in the pipe-engaging position to urge the plunger inwardly of the plunger chamber.

4. In power slips, a cylinder, piston means reciprocable in said cylinder for raising and lowering pipe-gripping slips to pipe-releasing and pipe-engaging positions respectively, conduit means for introducing pressure fluid into the cylinder connected to the cylinder at a point to urge the piston means to the slip-raising pipe-releasing position,

5 6 a pressure fluid actuated signal means connected to said pressure fluid is air and said signal means is an air-actuconduit means, valve means controlling admission of actuated whistle. ating pressure fluid from said conduit means to said signal means, said valve means having an operating member References Cited In the file 0f thls Pawnt engageable with a cooperating member carried by the 5 UNITED STATES PATENTS piston means when the latter is in the lowered pipe-engaging position to admit pressure fluid from said conduit fig gif g 2 2 means) Sald slgnalmeans- 2,759,448 Pitts Aug, 21, 1956 5. A power slip as defined by claim 4 wherein said 

